The first group of callatostatins to be isolated from Calliphora vomitoria, callatostatins 1 to 5, were shown to have some sequence homology to cockroach allatostatins (Duve et al in Proc. Nat'l. Acad, Sci. USA 90:2456-2460). The neuropeptides have the following sequences
1. Asp-Pro-Leu-Asn-Glu-Glu-Arg-Arg-Ala-Asn-Arg-Tyr-Gly-Phe-Gly-Leu-NH.sub.2 (SEQ ID NO:4) PA1 2. Leu-Asn-Glu-Glu-Arg-Arg-Ala-Asn-Arg-Tyr-Gly-Phe-Gly-Leu-NH.sub.2 (SEQ ID NO:5) PA1 3. Ala-Asn-Arg-Tyr-Gly-Phe-Gly-Leu-NH.sub.2 (SEQ ID NO:6) PA1 4. Asp or Asn-Arg-Pro-Tyr-Ser-Phe-Gly-Leu-NH.sub.2 (SEQ ID NO:7) PA1 5. Gly-Pro-Pro-Tyr-Asp-Phe-Gly-Met-NH.sub.2 (SEQ ID NO:8) PA1 1. Gly-Hyp-Pro-Tyr-Asp-Phe-Gly-Met-NH.sub.2 (SEQ ID NO:1) (designated Hyp.sup.2 !Met-callatostatin or Hyp.sup.2 !Met-cast) PA1 2. Gly-Pro-Hyp-Tyr-Asp-Phe-Gly-Met-NH.sub.2 (SEQ ID NO:2) (designated Hyp.sup.3 !Met-callatostatin or Hyp.sup.3 !Met-cast) PA1 3. Pro-Tyr-Asp-Phe-Gly-Met-NH.sub.2 (SEQ ID NO:3) (designated Met-callatostatin 3-8 or des-Gly-Pro-Met-callatostatin).
Callatostatins 1 to 4 (SEQ ID NOS:4-7) are know as Leu-callatostatins and callatostatin 5 (SEQ ID NO:8) is known as Met-callatostatin or Met-cast.
The allatostatin class of insect neuropeptides in cockroaches have been shown capable of inhibiting the production of juvenile hormone (JH) by the corpus allatum. The corpus allatum (CA) is a classical endocrine gland of insects situated in close proximity to the brain with which it has nervous connection. To date, members of the allatostatin class of neuropeptides have been isolated and identified in only four species, from three different orders of insects. In the cockroach, Diploptera punctata (Order: Blattodea) five allatostatins ranging in size from 8 to 18 amino acids have been characterized (Pratt et al in Proc. Nat'l. Acad. Sci USA 88, 2412-2416 (1991) and Woodhead et al in Proc. Nat'l. Acad. Sci. USA 86, 5997-6001 (1989)). Two other allatostatins have also been identified in the cockroach Periplaneta americana (Order: Blattodea) (Weaver et al in C Comp. Pharmacol. Toxicol. 107 119-127 (1994)) and in the tobacco hornworm moth. Manduca sexta (Order: Lepidoptera) a further allatostatin has been identified (Kramer et al in Proc. Nat'l. Acad. Sci. USA 88, 9458-9462 (1991)).
The significance of the allatostatins--(and callatostatins) lies in the fact that "in vitro" they have been shown, with the exception of the allatostatin from the tobacco hornworm moth, to inhibit the production of juvenile hormone (JH) by the corpus allatum in cockroaches. The allatostatin molecule isolated from the tobacco hornworm moth inhibits JH production in the species in which it is found i.e. Mandus sexta but not in cockroaches. Callatostatins 1 to 5 (SEQ ID NOS:4-8) are of interest because they are potent inhibitors of JH synthesis and release in cockroaches, but not in the blowfly, the species from which they originate.
Juvenile hormone plays a crucial role in insect development by controlling metamorphosis, adult sexual maturity and reproduction. Interference with juvenile hormone biosynthesis and release through exploitation of the allatostatins and callatostatins may lead to insect control strategies that do not damage the environment.